Method of printing.



C. W.. SAALBURG,

METHOD of Pas-xmms.

HLED APR.ZL`,196.

RENEWEU SEPI. 28 191].

12T/mw;

Patented July S, M15.

'l SHEETSSHEET l.

C W, SAALBURG.

METHOD OF PRNTING. APPLscATmN man APR, 29. 19m RENEWED SEPT, 2s, 1917.

Patented J uy S), 1918.

Z SHEETS 'SHEET 2 /Nl/E/v TUR A TTOR/VE Y such for example as shown in the CHARLES W. SAALEURG, or RICEMOND'HILL, NEW YORK, AssIGuoB. 'ro MULTIcoLoE. INTAGLIo PRESS COMPANY, 0E NEW YoRK, n. Y., A coRroRATIoN oF DELAWARE.

METHOD v0F PRINTING.

Applicatiil filed April 29, 1916, Serial No. 94,332.

To all 'whom z't may concern:

Be it known that I` CHARLES W. SAAL- BURG, Va citizen of the United States, residing at Richmond Hill, in the county of Queens and State of New York, have invented certain 'new and useful Improvements vin Methods of Printing, of which the following is a specification.

This invention is an improvement in thc art of printing. The ultimate object of the invention is the production of etched intaglio printing rolls or platesin short time and a lowcost, so that superimposed colors having a marked brilliancy of effect may be printed in a minimum time and at very low expense as compared with present methods.

Another object of the invention is to make the recesses, pits, or wells for holding ink orcolor inthe printing surfaces of printing rolls or plates, of uniform depth and of sufficient depth Vso that the printing surfaces will not comprise shallow pit walls which have been found to wear away so speedily that frequently in the printing of a large edition or job the light shading became obliterated -in consequence of the wearing away and destruction of the shallower pits which hold the ink for the light shading; and also to make such recesses, pits or wells of varying areas corresponding to the shadin'e areas desired for perfection of the color va ues in the final product. Such rolls or plates are an important economical feature of this invention.

One purpose of this invention forexample is to make it economically practicable to print newspaper supplements in superim` posed colors and with high artistic effects, speedily after the occurrence of any event which it is desired pictorially to illustrate in colors, and especially so to produce etched intaglio rolls tor use in either a multicolor web-perfecting or a sheet fed printing press,

'applic tion of Patrick H. McGiehan Serial No.

,100.183, fuedMay 27, 1916.

To print multicolor photogravure on a perfecting web press for. newspapers or where it is necessary to make several copper roll etchings quickly, is not commercially possible atrthe present time by the ordinary -Wellknown negative and positive Specification of Letters Patent.

' key rollv Fig.

Patented July 9, ISIS. RenewedA September 28, 1917. Serial No. 193,839.

photographic methods of color separation; or otherwise. By color separation is meant that the original color picture or scene is placed before the camera, and by what are termed color filters that are placed between the lens and a .sensitized dry plate, all the yellow that is in theV picture is exposed on one dry plate, separate color filters being used for the reds, blues and other colors, and the dry plates severally containing all the 'different colors of the original. Y

In'the accompanying drawings forming a, part hereof and illustrating my present mvent-ion, Vin part diagrammatically,

Figure l is ak top plan view of a superimposed, transparent mount, two photographic positives, and a sheet of photographically sensitized carbon graphic positives being between the mount and Vcarbon tissue and indicated in dotted lines. In one of the positives I have indicated in dotted lines a heart-shaped figure which is to be considered as vthe photographic image of any kind ot' a picture or representation. In the other positive I have indicated in dott-ed lines printed matter which is also to be understood as the photographic image of the tissue.

In the other drawings I have omitted all showing or the positive having the printed mat-ter, because indication of thev positive containing the heart-shaped figure indicative ofva picture image is understanding of the invention. A Fig.Y 2 is a cross-section corresponding to the line 2*2 of Fig. l.

Fig. 3 is a crosssection of a screen of any desired kind made of transparent material and of an initial carbon print in fiatwise assembla ge.

sufficient for an v paper or tissue, the photo- Y I"ig..4 is a View indicating an etchable copper roll on the surface of which the carbon screen print has been transferred; and

F ig. 5 is a view of the roll man vetched condition, the etching showing the heartshaped figure indicative of a picture; and the etched roll here shown is hereinafter called thev key roll.

Fig. 6 is a plan vieu7 of a key sheet of transparent material such as celluloid, for example, on which the figure shown on the 5) has been printed with iight blue ink for example.

Fig. 7 is a plan view ofa superimposed assemblage of a key-sheet covered on its A `printed side with a transparent reproduction sheet; and Y Fig. 8 is a cross-section of such Yassemblageat line 8 8 of Fig. 7.

Fig. 9"is a top plan viewV of a superimposed assemblage of a key-sheet with' a reproduction sheet thereon of transparent material such as celluloid, and on which has been art-worked a portion of the underlying picture indicated by the heart-,shaped ligure referred to, such portion being assumed to be in one of four colors,-black, red, yellow and blue, commonly used in four-color printing.

' Fig. 10 is a view similar to Fig. 9 but in which the art-worked portions of the heartshaped figure are art-worked in diiferent colors. Fig.` 11 is an illustration ofthe artworked face of reproduction sheet wherein the color deposited in the art-working is graphically and exaggeratedly indicated by black dots of varying sizes, and two rectangular black iigurations. These round and rectangular figurations indicate some of the many piles or thicknesses of color which are laid on. the surface of a reproduction sheet and which correspond to the dots, grains', stipple or other artwork whereby color and shade values are eifected in theart-work drawing. i

Fig. 12 is a cross-section at line 12-12 of Fig.' 11, and exaggeratedly indicates one of the many piles of color deposited on the re-v production sheet when the art-work drawing thereon is made.

Fig. 13 is a partial view of a printing roll which has been etched and wherein the inkreceiving spaces, pits, or wells, are also shown of eXaggerat/edly varying areas, but

of uniform depth, these .being due to the' varying areas and uniform height or depth of the deposited color shown in the artworking-illustrated by Fig. 11.

Fig. 14 is a top plan view of a transparent key sheet and, reading upwardly from the key sheet which is at the bottom of the stack, of an art-worked reproduction sheet, here used as a photographic positive, of a sheet of photographically sensitized carbon paper or tissue and of a transparent screen of any suitable configuration; and

Fig. 15 is a cross-sectional view of t-he assemblage shown in Fig. 14 at line 15-15 thereof. l V

Fig. 16 is a view of a printing roll having transferred toits surface the final car bon tissue print; and

Fig. 17 is aview of the same print roll, etched,

Fig. 18 is a cross-section of a printing roll to'be etched in assemblage with a. final carbon tissue print assumed to have the image of the picture and overlaid with a carbon screen print.

lWhen, in such duplicates of thel subject were to be placed on one roll to be duplicated on all the other rolls, made on glass as vIna-ny duplicates of the color negatives and color positives aswere required to complete the rolls; and

then cut out a large piece of sensitized carbon paper and placed in a photographic printing frame all the positives with the large carbon sheet over the positives under good pressure, and took the exposures for the various colors. If the work required four colors for example, I made'a set of' black, yellow, red, and blue positives. Such work involved a long operation, and particularly so when each color positive had to be retouched separately. @ne of the greatest objections, however, encountered, was nonuniformity in the thickness of the glass dry plates obtainable in the` public market. My experience has been that when these separate glass positives are placed in a printing frame and the thin carbon sensitized paper is pressed over the glass positives which are of varying thicknesses, non-uniformityof print occurs on the carbon'paper, and that such objectionable non-uniformity is repeated on each color forni so that when the llarge carbon print is transferred on a copper plate or roll, a diierence of registration in all the colors is brought about' by the inaccuracies arising from the non-uniform thicknesses of the glass positives and the open spaces between the glass mounts.

Photographic color sepa-rations are usually made one at a time so that the above4 conditions cannot be readily changed by Y making anA exposure on a single sheet of all the pictures that are required to be etched on one roll. Therefore it has been necessary heretofore to use separate glass plate negatives. Setting up these separate negatives, that is mounting them on a large piece of plate glass used as a transparent mount, is expensive land inaccurate, and involves slow operation for such transparent negatives have to be mounted byeye through the thickness of a glass positive and when the operation was repeated four times for ex ample, once for each set of four colors, final correct registration was very uncertain. if they doA not register on the inal etching there is no Way to rectify the mistakes and thecopper roll has to be turned downY for another etching.

For superimposed multicolor intaglio printing where several color rolls are to be used for printing whether-on a sheet or on a traveling web, a rapid, inexpensive and accurate process must be devised to produce the final result, particularly for newspaper editions. -l

n this connection l may say that dat older processes, severalT narines Y V plates, or curved plates, or 'dat bendahle plates of etchable material, are deemed,

equivalents of the copperrolls mentioned.

One important feature of my invention is to make the final carbon print to he transferred to the rolls or plates as hereinafter described, from a. carbon print in iatwise assemblage Vwith a.' grain, dot, or stipple screen, and not with a line screen, in order to avoid moir antique or checkerboard effects inthe printed product, unless the carbon print is made from a half-tone, dot or grain or stipple positive, in which case e' line screen may be used with the carbon print-Without producing moire antique etects if the lines of the line screen do not in# tersect the dots, grains or stipple.

For the production of etched intaglio printing rolls or plates according to my present invention, my procedure, depending on the nature of the subject, is as follows:

First. IVhen it is desired to produce etched rolls or plates for the printing of pictures in arbitrary colors,as distinguished from the coloration given by an artist to the picture which it is intended to reproduce.

l. I place either one or more photographic positives 1 on a suitable transparent mount 2 and place a sheet 3 of photographically sensitized carbon paper having the usual gelatin or like content, over the positive i positives (Figs. 1 and 2), and by exposure 1n a printing frame make an initial carbon print from the positive or positives.

2. I then assemble such initial carbon print 2a in latwise contact with a grain, dot, stipple or line 4 screen of transparent mate rial (Fig. 3), and expose the assembledV print and screen in a printing frame.

3.A I then transfer the lat-ter, or what I will call the carbon-screen print 2b, just made,rto a metal roll -or plate (Fig. 4), and develop and etch the roll or plate-to form a key roll or a key plate. Fig. 5 shows the etching on the roll at 6.

' 4. From such key roll 5 or key plate, placed in a printing press, I rint on a series of transparent sheets 7 W ich are prei"- crably of Celluloid, as many different impressions as are required for the additional printing rolls or printing plates required to be etched,according to the number of colors to be printed. Thus I form a series of printed transparent key sheets 7. These key sheets are printed 8 with. a light blue' or other ink or compound which will not print when in a later step the key plates are cxposed in connection with sensitizedcarbon paper and a reproduction sheet and a screen.

5. I then cover each key sheet 7 with a transparent reproduction sheet 9, preferably of Celluloid, keeping each superimposed key sheet and reproduction sheet in lixed relation one to the other, and reproduce in opaque ink or material from 'the underlying key sheet on the outward surface of the reproduction sheet, by means of inking up tinting films or other suitable process, means or procedure, the part or parts of the underlying key sheet which corresponds to the color areas 1G, 1l, 12, for examples, that are to be subsequently etched on the rolls or plates. There are many Ways in which an artist can draw, paint, crayon or transfer ink onto the reproduction sheets preparatory for final resuits, art-working as many of such sheets as may be required. Figs. 7 and 8 show one of the key sheets 7 Vassembled with one of the reproduction sheets 9 art-worked in different colors 10, 11 and l2, and in Fig. 1G another portion or the picture is art-Worked in a fourth color 13.

The reproduced part or parts are in opaque dots, grains, ruh tints,. stippie, or line, and the outward surface of the reproduction sheet if preferred may be grained like a lithographie stone and pigment placed thereon, as on stone. The dots, grains, stipple or other art work W on the reproduction sheet, are of varying areas (Fig. 1i) corresponding to the shading to be used for the color values in the finally printed product, and they are also of substantially equal density, as shown in solid black in Fig. il, in order to ei'ect linally a uniform depth of etching-that is to say, a substantially uniform but suiiicient ,depth ofthe ink-holdingV recesses 14 which will -be of varying ing areas of the dots, grains, stipples and the like of the art work VJ.

Inasmuch as each reproduction sheet is fixed in its superimposed position on a key sheet during the performance ot the art work on the reproduction sheet, it follows that registration ot' the work done on the reproduction sheet may be, according to the skill of the Workman, in absolute registration with the picture on the underlying key sheet.

6. I 'next take each'set of assembled key sheets 7 and reproduction sheets 9 in their said fixed relations one to another, and assemble each set as a positive with a sheet of photographically sensitized carbon paper 15 havino' the usual gelatin or similar coutent, and z so with a suitable transparent screen 16, andmake an exposure ot such assemblage, which comprises a key sheet. having areas (Fig. 12) in consequence of the varybon paper or tissue, it will sometimes be preferable to use the smaller sheets referred to, one for each figure or picture, on a sheet mount. A Celluloid sheet such as used for the key Sheet above mentioned may be used as the mount for such series of carbon tissue prints, as sufficiently illustrated 1n Fig. l.

If it is desired to ive a fine tooth or grain to the outward sur ace of the reproduction sheet or sheets, such tooth may be effected by washing the surface with amyl acetate, for example.

Preferably the key sheets 7 are made of rather still' transparent- Celluloid to insure stability and to insure against stretching or shrinkage,`and preferably the reproduction sheet or sheets 9 are made of thinner transparent celluloid, and made quite thin in fact, so that very accurate' reproduction of the underlying subject or subjects is facilitated. Thin reproduction sheets may be effectively and uniformlyv pressed home in the printing frame on the key plates. The light blueor other suitable non-printin delineation on the key plates prevents suc delineav tion or picture from printing simultaneously with the .art Work in the final assemblage.

The above procedure is cheap, accurate and rapid, and does away entirely with photographic color negatives and positives. By reason of every dot, grain, stlpple or the like being of the same density of pigment, the etching acid will bite through the dots, grains, stipple or other deposit in an equal time, and therefore bite into the copper in the same time and form ink-receiving' -recesses of equal dept-h Whose areas willV be severally in accordance with the areas. vof the dots, grains, stipples and the like. This is a fact, as 1 find in actual experience, and secures Working durability to the printing rolls or plates.

7 There is an additional step of a useful nature, but which is not absolutely essential though frequently desirable, as follows (see Fig. 17 z I may make the initial carbon paper exposure of the positive, transfer the resulting carbon print film 2b to the roll or plate, and dry; and subsequently take a sensitized carbon paper exposure of thev screen which it is desired to use and transfer such second resultant film 17 over the first dried film, developing the latter film and drying.

Thus there will be two films for acid enetration instead of one, and this assem lage effects 'in the etching greater depth and strength, and effects greater detail in the printed product. yThe superimposed film also covers up any small specks or defects in practical economy.

' desirable in warm and humid weather when Vthe films are apt to decompose.

The above procedure is especially useful when a full page illustration, for eXample,is required, as generally for magazine covers, and often in making large prints in newspaper supplements; or when a large sheetis to be printed with a plurality of pictures.

Second. lVhen it is desired to produce etched printing rolls or plates for the printing of pictures in the same or approximately the same colors, shades and tones thatthe artist has used in the picture to be reproduced, then one may economically avail of lithography as a step in the production of positives for use in the first step in the abovedescribed procedure,that is, for the production of the initial carbon print.

Such use of Vlithogrzqihy is especially adapted to enable the artist to see on paper his finished color results from a subject on a. lithographie' stone and before he begins to etch the rolls or plates. This is a matter of The present use of lithography as a step in my invention eliminates the necessity of using photographic negatives and positives, and color separation mistakes cannot happen because the operator will have a proof on paper before the etchingV the underlying film which would cause whatVV are commonly called devils in the etched drawings of the subject as may be required by the crayon, half-tone, stipple or any otherl appropriate means or medium.A He then makes a combination proof on paper of the several colors.- Thereupon, asA another step, one may take a series of sheets of transparent Celluloid orot-her suitable material, one for each color, and make thereon a lithographic transfer from 'the stone with black iigment. lf the Work requires, for instance, four duplicates, he makes four transfers on separate sheets of celluloid, one for each of the lfour colors, and each such sheet is a positive suitable vfor luse in printing the initial carbon print referred to above'. Thus the requisite positives are produced without the aid of photography. The advantage which this lithographie step involves as compared with the photographic separation process is, in addition to its being superior for duplicating more cheaply and quickly, that a photogravure etched from a dry plate positive is made by etching different tones of the positive, and that it takes great skill to do such work; it being impossible unless by accident above referred to,

from lithographie stones with black ink on although the non-printing Vcially 'smooth tones as in a dry is observed but When all the tones on a aan;

to V'etch two photographic positives o the` Vsame subject at different times and get the same tones. In fac-t the diiierence is very marked, and the rolls or plates must Vbe manipulated to a great extent after the main etching work is completed. This is espetrue with reference to multicolor Work. That l may call my lithographie positives and which are transfers celluloidor other transparent material, have the advantage that every dot, tone or tint on the lithographie stone is of the same density of color and the picture is made by use of diii'erent sizes of the black dots, grains, stipples, lines or the like, and not Vvby flow of plate positive.

Generally stated,the chief improvement While the etching is in progress. A gelatin carbon print made from a dry plate positive has to be' etched by diiierent strengths of a suitable acid such as chlorid of iron solution. Penetration of different thicknesses of the` gelatin print is uncertain and dependent upon skill and understanding of the temperature and humidity conditions, gelatin print are produced with dots of equal density, the picture being made of dots, grains, stipple or the like of varying areas, then all the parts of the film are-attacked at once on application ofa single acid of suitable strengt and the etching is lautomatically effected Without the constant observation and use of several diiferent strengths of acids as heretofore; and moreover each etching, if the same' time is given for the automatic operation with the single acid, will be substantially identical with every other etching of the saine series.

The use of akey plate printed or impressed with a picture made in light blue ink or other material Which Will not print in the printing of thelinal sensitized carbon paper print, is not an absolute essential because it is not absolutely essential that the key sheet be used in making that final carbon print which is to be transferred to an etchable roll or plate. However, if the key sheet and reproduction sheet be disassembled, there will be undesirable Waste of time and labor and inconvenience when and where quick and most economic results are wanted; and if the key sheet happens in any given case to constitute amount for a plurality of reproduction sheets, then in case of disassemblage much labor and diiiieulty Will be necessary in order to arrange the plurality of reproduction sheets symmetrically andfor the exact registration required in an assemblage of a plurality of reproduction sheets with a carbon paper sheet, With 0r Without a screen for the final print. Thus key-sheet is a dead or inactive element inthe final printdots, grains, stipple and the like on the re-' production sheets may be generically referred to as patches of varying areas and substantially equal density. of the use of such patches is that the carbon print havinga gelatin or similar content printed by exposure to light from such art- Worked sheet, whentransferred to an etchable roll or plate, can be immersed in a bath of a suitable etching acid which bites through the patches of equal vdensity but of varying areas in the same period of time, so that the acid bites into and forms in the etchable surface the ink-holding recesses of varying areas and of equal depth. The etching operation is thus automatic. But of course theetching may be done in Whole or in part by manual application of the acid in the usual way, it so desired.

Ihave hereinbefore referred to screens. The color separation operation which is avoided by my invention, involves the use of cameras provided with socalled color screens. Such screens are not used. I have referred to inking-up films. Some varieties of such `films are commonlyknovvn as Ben Day films. l have referred to other screens as line screens. glass and ruled with lines in various directions one to another; I have also hereinbeavoided and at the same time devils are avoided, and also, and What is particularly important in textile printing, get an increased depth of tissue for etching and thereby obtain an increase of depth of the ink-holding holes or recesses, which increase of depth as compared with the depth obtainable by etching through the negative tissue only, is a very positive advantage, especially in textile printing, because a greater quantity of ink is had on the doctored roll than would otherwise be the case,

These are ordinarily 'of i An important result and such increase` of depth of ink enables the printing-couple pressure better to force the lnk through the fabric from the front to the rear side so that the printed figure will appear on the backside ef the goods asis required in many lines o-printed textiles. 'rf

I The part or parts of the roll or plate that are not to be etched are coated with an acidresist material which prevents the etching acid from attacking such parts.

In the textile printing art, the 'artists who draw the original designs for engraved rolls made by the pantograph machine, customarily make what' are called allowances; that is, spaces between different coloration parts, to'allow for the spreading or springing of the colors used in printing. By my invention the diiliculties arising from allowances are overcome because of the great multiplicity of cells in the etched roll or plate instead of the non-cellular spaces and deep continuous cavities inherent in engraved rolls. Another advantage of my invention, in its application to textile printing, lies in the fact that when a given pattern drawn b v an artist has to be repeated with pattern figuration joined in order to 'cover a roll or plate with a continuous pattern, my repeats are readily made by reversing some of the thin celluloid positive reproduction sheets which are thin enough for use as printable positives whichever side is against the sensitizedcarbon sheet. ln the case of glass positives, the glass is so thick as to throw the exposure off on the carbon paper if it were attempted to print from the back surface of such glass positive.

l do not herein claim the use of the exterior film for obliterating defects of the underlying film and the avoidance of devils because the same forms the subject-matter of my i ing rolls or plates for multicolor printing,

'consisting in making, without use of color separation screens, a carbon print having a gelatin or like content, of a picture to be reproduced; in assembling such initial print tlatwise with a transparent screen and exposing such assemblage to light; in transferring such screen print to an etchable roll or plate and etching the same to forma key roll or key plate; in printing from such key roll or key plate a series of impressions on transparent sheets, one impression for every additional color roll or color plate required, and thereby making a series of transparent key sheets; in fixedly and flatwise assembling each such key sheet with a transparent reproduction sheet; in art-working in opaque patches of varying areas and equal density on each reproduction sheet t-he part pending application Serial No. 151.169, filed February 27, 1917.

or parts of the underlying key sheet that are correspondent to the particular color required in a corresponding part or parts of the reproduction to be printed in superimposed colors; in assembling each such artworked transparent reproduction sheet with a sheet of sensitized carbon paper having a gelatin or like content and exposing such assemblage to light; in transferring each carbon print last-named toan etchable roll or plate; and in subjecting each such roll or plate and the transferred carbon print on it to a suitable acid and thereby producing in the printing surface ofthe roll or plate, ink-holding recesses ot' varying areas and of substantially uniform depth.

2. The process of making etched printing rolls or plates for multicolor printing, consisting in making, Without use of color separation screens, a carbon print having a gelatin or like content, of a picture to be reproduced; in assembling such initial print Hatwise with a transparent screen and exposing the assemblage to light; in transferring such screen print to an etchable roll or plate and etching the same to form a key roll or key plate; in printing from such' keyroll or key plate with an ink or the like that will not print in a subsequent light-printing operationa series of impressions on transparent sheets, one impression for every additional color roll or color plate required, and thereby making a series of transparent key sheets; in lixedly and iatwise assembling each such key sheet with a transparent reproduction sheet; in art-working in opaque patches of varying areas' and equal density on each reproduction sheet the part or parts of the underlying key sheet thatare correspondent to the particular color required in a corresponding part or parts of the reproduction to be printed in-superimposed colroll or plate ink-holding recesses of varying areas and of substantially uniform depth.

3. The process of making etched printing rolls or plates for multicolor printing, consisting in making, without use ot' color separation screens, a. carbon print having a gelatin or like content ot' a picture to be repro"- duced; in assembling such initial carbon print ilatwise With a transparent screen and exposing the assemblage to light; in transferring such screen print to an etchable roll or plate and etching the same to form a key narrate roll or key plate; in printin from such key a corresponding part or parts of the reproduction to be printed in superimposed colors; in assembling each such art-Worked transparent reproduction sheet and its underlying key sheet in fixed relation thereto, with a sheet of sensitized carbon paper having a gelatin or like content and also with a screen and exposing such assemblage to light; in transferring each carbon print lastinade to an etchable roll or plate; and in subjecting each such roll or plate and the transferred carbon print on it to a suitable acid and thereby producingr on the printing surface of the roll or plates ink-holding recesses of varying areas and of substantially uniform depth. Y

4. The process of making etched printing rolls or plates for multicolor printing, consisting in making art-work in patches of varying areas and substantially equal densities on a transparent sheet; in making a carbon print from such transparent sheet; in transferring suchV print to an etchable roll or plate; and in subjecting the roll or plate with the transferred film on` it to an acid bath and thereby biting into the roll or plate ink-holding recesses of varying areas and substantially equal depths.

5. As an improvement in the art of printing from a series of etched rolls or plates each having a plurality of etchings that areA required to be registered accurately one with another in the press printing operation, a process consisting in placing a plurality of photographic carbon tissue positives on a mount which isdetachable from the positives; in transferring such positives from the detachable mount to a press printing surface to be etched: inietching such surface and thereby forming a. key press printing surface having a plurality of etched portions; in making a press printed impression on a transparent sheetfrom the key press printing surface in an ink which will not print photographically, in order to form a' key sheet; in assembling such key sheet with a transparent reproduction sheet; in reproducing on the reproduction sheet such part or parts of the representations on the underlying key sheets as may be desired; in assembling the so-worked reproduction sheet with a sheet of sensitized carbon tissue; in exposing such assemblage in a photographic printing frame and making a photographic car-V bon tissue print.; in transferring such last carbon tissue print to another press printing surface to be etched; and in etching such second surface; whereby two etched press printing surfaces each having a plurality of etched i portions are produced, thc corresponding etched portions of the two press printing surfaces being in exact relatively registering positions one to another.

6. Aswan improvement in the art of printing from a series of etched rolls or plates each having a plurality of etchings that are to be registered one with another in a press printing operation, a process consisting inV placing a plurality of photographic carbon tissue positives on a mount detachable from the positives; in transferring such positives from the detachable mount to a press printing surface to be etched; in etching such surface and thereby forming a key press printing surface; in making a press printed impression on a transparent sheet from the key press printing surface in an which will not print photographically, in order to form a key sheet; in assembiing such ke i sheet with a transparent reproduction sheet; in reproducing on the reproduction sheet such part or parts of the reproductions on the underlying key sheet as may be desired; in assembling the so-treated reproduction sheet with a plurality of sensitized carbon tissue sheets; in exposing such assemblage in a photographic printing frame and making a series of photographic carbon tissue'fprints; in placing these several prints on a mount in positions correspondent to the positions of the positives on the first mount; in transferring the last series of photographic Vcarbon tissue prints from their mount to a second press printing surface to be etched; and in etching such second surface; whereby two etched printing surfaces each having ay plurality of etched press printing portions are produced, each etched printing portion of one printing surface being positioned exactly to register with a corresponding etched portion on the other press printing surface.

7. The process of making a series of etched rolls the etched printing surfaces Whereoz are exactly registra-ble one with another, consisting in transferring a carbon tissue print comprising one or more representations to be finally printed to an etchable pressprinting loodyv and in etching such body by use of a. suitable acid; in taking an impression from such etched body on a Vtransparent sheet; in assembling such impressioned sheet with a sheet of sensitized carbon tissue; in making from. such assemblage a photographic carbon tissue print; and in transferringsuch carbon tissue print to another etchable pressprinting body and etching the same by use of a suitable acid.

8. The process of making a series of etched 5 'n'nted in colors; in taking an impression -trom such key body on a. transparent sheet in an ink o1:V medium that will not print -photographically, to form a key sheet; in flatwise assembling such key sheet with a .0 transparent reproduction sheet and Working thereon in a medium that will print photographicully such portion of the key-sheet representation :is is to be nal1yprinte in a eolor other than that to lie printed by the key press-printing body; 1n assembing the worked reproduction sheet with a sheetof sensitized carbon tissue and making a. carbon tissue Vprint by exposure to light; in trans-V ferring such exposed carbon tissue printt0 a. i

press-printing body to be etched; and in etching it.

In testimony whereof I have hereunto set 'my hand this 25th my @Api-i1, 1916.

CHARLES w. .SAALBURQ 

